With the advancement in the state of the art, modern molded case circuit breakers have become more compact and yet provide current ratings and interrupting capacities comparable to their bulky ancestors for most applications. In addition, modern circuit breakers afford considerable economics in materials and manufacturing costs. Yet there remains significant demand for these bulky, old style circuit breakers, mainly as replacement molded case breakers for service entry equipment installed years ago. Naturally, there is an extreme reluctance on the part of any manufacturer to discontinue production of components needed only as replacements by past customers of old style equipment which remains serviceable. To do so would likely alienate these old customers and could well jeopardize future sales. Yet, to maintain manufacturing facilities for both the old style and new style equipment is extremely expensive, and, to exacerbate the situation, the manufacturer typically can not charge a price for the old style equipment sufficient to recover full costs. Thus, maintaining the availability of old style equipment is normally an unprofitable enterprise which is endured as a service to accommodate past customers.
In recent years, circuit breaker manufacturers have been marketing protective devices which provide not only the traditional overload and short circuit protection, but also ground fault protections. Such devices, termed ground fault circuit interrupting (GFCI) devices, are currently being offered in a compact circuit breaker configuration for installation in modern service entry equipment as a direct substitute for the compact, new style molded case circuit breakers affording only traditional circuit protection, i.e., overload and short circuit protection. Unfortunately users of the old style service entry equipment can not avail themselves of the additional ground fault protection afforded by GFCI circuit breakers, simply because these modern GFCI devices are not readily accommodatable in their equipment, both from physical and electrical standpoints.
It is accordingly an object of the present invention to provide a circuit breaker assembly having the physical size of an old style breaker and the manufacturing economies of a new style breaker.
An additional object is to provide a circuit breaker assembly of the above-character offering the full measure of modern day circuit protection and yet can be conveniently retrofitted in old style service entry equipment.
A further object is to provide a circuit breaker assembly of the above character which is convenient to assemble, inexpensive to manufacture and reliable in operation.
Other objects of the invention will in part be obvious and in part appear hereinafter.